Russia has launched a new initiative to end the conflict in Syria, calling for a time-bound ceasefire that should be guaranteed by main outside powers.

“We have proposed calling a new ceasefire that this time would be under the responsibility of outside players who wield influence both on the government and armed opposition,” said Russia’s Foreign Minister Sergei Lavrov.

International guarantees would help assure both the government and the rebels that neither side would take advantage of the ceasefire to tip the balance in its favour. Fears of unilateral advantage wrecked the ceasefire declared in Syria in April.

Russia planned to discuss its new initiative for a at a meeting of the Syria Action Group of world powers in New York on Friday, but the meeting was called off as Western powers refused to attend.

Mr. Lavrov said the ceasefire would pave the way to implementing a peace plan agreed upon by world powers at a meeting of the Action Group on Syria held in Geneva in June. It called on the Syrian government and the opposition to halt violence and appoint negotiators who would form a joint “transition body.”

The Russian Foreign Minister denounced as “irresponsible” U.S. claims that the Geneva accord was “dead.” He said such claims betray a plan to resort to military interference in the Syrian conflict.

“This is a road to big catastrophe in the region,” Mr. Lavrov said in an interview to Sky News Arabia, which was posted on the Russian Foreign Ministry’s website on Saturday.

Mr. Lavrov rejected U.S. calls for a “no-fly zones” over Syria.

Secretary of State Hillary Clinton said last week that Washington and Turkey were looking at all measures to help Syrian rebels fighting to overthrow President Bashar al-Assad, including a no-fly zone.